Mexiletine Has No Effect on Defibrillation Energy Requirements in Dogs

Many of the antiarrhythmic drugs produce a rise in the ventricular defibrillation threshold (DFT). Although mexiletine has also been reported as the probable cause of a significant elevation of DFT, there has been no previous study; therefore, the effect of mexiletine on DFT was investigated in the present study. The experiments were performed on ten mongrel dogs in the open-chest state using general anestbesia. Mexiletine 1,2,4, 6, or 8 mg/kg was administered as the loading dose, followed by the same dose/kg per hour. In these five groups, fibrillation/defibrillation (F/D) trials were performed repeatedly every 10 minutes, until 60 minutes after starting the maintenance dose. F/D trials were also performed at 30, 45, and 60 minutes after the completion of mexiletine infusion. The heart was allowed to fibrillate for a total of 30 seconds. Applying internal paddles to the beart, energies of 2, 3, 5, 7, 10, 20, and 30 J maximum were used. The minimal energy shock that caused defibrillation was defined as the DFT. The mexiletine concentration in each group cbanged from 0 to 6.11 μg/mL, DFT ranged from 2–10 J, and no statistical correlation was found between mexiletine concentration and DFT. We conclude that mexiletine does not induce an increase in DFT in dogs.     

Importance of mechanical damage to urinary red blood cells by the glomerular basement membrane

The reasons for morphological changes of urinary red blood cells (RBC) in patients with glomerulonephritis are still controversial. In order to evaluate the importance of mechanical damage by the glomerular basement membrane (GBM), we examined urinary RBC taken from the patients with two different diseases which have characteristic GBM changes. Urinary RBC taken from 20 patients with Alport syndrome and nine with thin GBM disease were examined using a scanning electron microscope. Nineteen out of the 20 patients (95.0%) with Alport syndrome showed ‘glomerular type’, while five of the nine patients (55.6%) with thin GBM disease showed ‘glomerular type’. These results suggest that more complicated GBM abnormalities cause more severe RBC distortion. Therefore, we conclude that mechanical damage by the GBM may be the major factor in dysmorphism of urinary RBC.     

Idiopathic retroperitoneal fibrosis associated with IgG4-positive-plasmacyte infiltrations and idiopathic chronic pancreatitis

Idiopathic retroperitoneal fibrosis (IRPF) is an inflammatory fibrosclerosing condition, leading to renal failure by obstruction of the ureters. Idiopathic chronic pancreatitis associated with marked inflammatory infiltrates has recently been referred to as autoimmune pancreatitis (AIP), and infiltrating plasmacytes carrying immunoglobulin-gamma type 4 (IgG4) are relevant to its pathogenesis. The case is described herein of IRPF associated with subclinical pancreatitis that was most probably AIP in a 70-year-old man. Biopsy specimens of the retroperitoneal pseudotumor revealed a marked lymphoplasmacytic infiltration with dense fibrosis. Infiltrating plasma cells were immunoreactive for anti-IgG4 antibodies. Subsequent systemic examinations showed an extremely elevated serum IgG4 level and pancreatitis concordant with AIP. Following oral steroid administration, the serum IgG4 level normalized, although the appearance of the pseudotumor did not alter. Some AIP cases have been associated with idiopathic fibrosclerosing disorders including IRPF, but histological evidence of IgG4-related IRPF has rarely been provided.     

Risks of antipyretics in young children with fever due to infectious disease

The objective of this study was to determine whether paracetamol (acetaminophen) affects the outcome of children with fever due to bacterial infectious disease. A total of 208 outpatients aged 6 months to 15 years with pyrexia due to bacterial infection who had been examined at the Fujimoto Children's Hospital from March 1992 to May 1992. The number of antipyretic doses of paracetamol (10 mg/kg) a day received within 3 days of illness in the patients with acute fever (≥ = 38°C) was investigated. In this study, the patients were divided into two groups: (i) the pneumonia group, which consisted of 101 patients who were subsequently diagnosed as having pneumonia during their illness and (ii) the control group, which consisted of 107 patients who were subsequently diagnosed as having illness with fever that did not progress to pneumonia. The mean number of daily doses was significantly higher for the pneumonia group (2.52 ± 0.80) than for the control group (1.37 ± 0.72, P < 0.001). There was no significant difference between the pneumonia group and the control group in body temperature during acute fever (38.7 ± 0.65 vs 38.8 ± 0.54°C). The data suggest that frequent administration of antipyretics to children with infectious disease may lead to a worsening of their illness.     

Predictors of prostate cancer on repeat transrectal ultrasound-guided systematic prostate biopsy

BACKGROUND: We analyzed the outcome of repeated transrectal ultrasound (TRUS)-guided systematic prostate biopsy in Japanese men whose clinical findings were suspected of prostate cancer after previous negative biopsies. METHODS: Between January 1993 and March 2002, 1045 patients underwent TRUS-guided prostate biopsy. Among them, 104 patients underwent repeat biopsy due to indications of persistent elevated serum prostate-specific antigen (PSA), abnormal digital rectal examination (DRE) or TRUS, increased PSA velocity, and/or previous suspicious biopsy findings. Several clinicopathological factors were evaluated for their ability to predict the detection of prostate cancer on repeat biopsy. RESULTS: Prostate cancer was detected in 22 of 104 patients (21.2%) who underwent repeat biopsies. PSA concentration and PSA density at both the initial and repeat biopsies, and PSA velocity in men with positive repeat biopsy were significantly greater than those in men with negative repeat biopsy. The incidence of abnormal findings in DRE and TRUS at initial biopsy in men with positive repeat biopsy was also significantly higher than that in men with negative repeat biopsy. However, neither the presence of prostatic intraepithelial neoplasia nor number of biopsy cores at initial biopsy had a significant association with the results of the repeat biopsy. Furthermore, multivariate analysis revealed that PSA and PSA density at both the initial and repeat biopsies, PSA velocity, and DRE and TRUS findings at initial biopsy were independent predictors of malignant disease on repeat biopsy. CONCLUSION: Despite an initial negative biopsy, repeat TRUS-guided biopsy should be carried out to exclude prostate cancer in cases of suspicious clinical findings, such as elevated PSA or PSA-related parameters, or abnormal findings of DRE or TRUS.     

Churg–strauss syndrome: importance of colonoscopy and endoscopic biopsy in establishing diagnosis

A 31‐year‐old Japanese man was admitted with complaints of left lower abdominal pain and diarrhea. He had a history of bronchial asthma since he was 26 years old. On admission, his eosinophil count was 4100/mm ³ and increased as high as 12 000/mm ³ . A neurological examination disclosed mononeuritis multiplex with paresthesia in both lower and upper extremities. Because of hematochezia, colonoscopy was performed and disclosed multiple colonic ulcers and erosions from the rectum to the ascending colon. Endoscopic biopsy showed fibrinoid necrosis of small‐sized vessels with moderate infiltration of eosinophils in the mucosa and submucosa. He was suspected of being a case with Churg–Strauss syndrome (CSS; allergic granulomatous angiitis), and prednisolone of 30 mg/day was administered. After the administration of prednisolone, his eosinophil count decreased dramatically. His symptoms also improved gradually, except for numbness in the extremities. Three weeks later, colonoscopy revealed improvement of the mucosal appearance, but the colonic ulcers and erosions were still present. Endoscopic biopsy showed exravascular granuloma with moderate infiltration of eosinophils in the submucosa. Colonoscopy and endoscopic biopsy may be important in establishing the diagnosis of CSS with intestinal symptoms.     

Liver abscess that developed after a long interval of transcatheter arterial embolization followed by formation of hepatoduodenal fistula

A 55‐year‐old male patient with hepatocellular carcinoma underwent transcatheter arterial embolization (TAE). He became febrile and experienced pain at the right hypochondrial region 323 days later, which led to the discovery of a liver abscess that fistulated into the duodenal bulb. There have been no reports on the fistulation of liver abscesses into the digestive system following TAE. Rhodococcus equi was isolated as a causative agent, which distinguished the case further.     

Combined small cell carcinoma and sarcomatoid squamous cell carcinoma in the renal pelvis

We report here a case of combined small cell carcinoma and sarcomatoid squamous cell carcinoma in the renal pelvis. A 61-year-old female presented with right flank discomfort, microhematuria and progressive renal dysfunction. Following diagnosis of right renal pelvic carcinoma, radical nephroureterectomy with lymph node dissection was performed through a midline incision. The tumor was pathologically diagnosed to be combined small cell carcinoma and sarcomatoid squamous cell carcinoma in the renal pelvis. The patient had no evidence of recurrence or metastasis, 16 months postoperatively. Small cell carcinoma or sarcomatoid squamous cell carcinoma of the renal pelvis is very rare. We believe this is the first such case to be reported in the world.     

A case of Kabuki make-up syndrome with central diabetes insipidus and growth hormone neurosecretory dysfunction

A case of a 6 year old boy with Kabuki make-up syndrome with central diabetes insipidus and growth hormone neurosecretory dysfunction is reported. Magnetic resonance imaging revealed abnormal findings of the pituitary gland and stalk. Good catch-up growth was obtained by treatment with growth hormone. These findings suggest that hypothalamic-pituitary dysfunction might be involved in Kabuki make-up syndrome.     

Deficiency of Testosterone Associates with the Substrate of Atrial Fibrillation in the Rat Model

Background: Since the prevalence of atrial fibrillation (AF) increases progressively with aging, especially in men, we hypothesized that testosterone might affect the occurrence of AF.
Methods and Results: We examined the electrophysiological properties of the atria in isolated-perfused hearts of sham-operated male (SM), female (SF), orchiectomized male with and without administration of testosterone (ORCH-T and ORCH), and ovariectomized female (OVX) Sprague-Dawley rats. An electrophysiological study revealed that repetitive atrial responses induced by electrical stimuli significantly increased in ORCH rats without changes in other electrophysiological properties and were abolished by administration of testosterone. To investigate the underlying mechanisms, we evaluated the expression level of calcium-handling proteins. In ORCH rats, the immunoreactive protein level of ryanodine receptor type 2 (RyR2) and sodium–calcium exchanger significantly increased as compared with SM and ORCH-T rats without alterations in the level of FK506-binding protein (FKBP12.6), sarcoendoplasmic reticulum Ca-ATPase, and phospholamban. Immunoprecipitation analysis demonstrated decreased binding of FKBP12.6 to RyR2 in ORCH rats, which was prevented by testosterone. In contrast, the expression levels of these proteins showed no significant differences between SF and OVX rats.
Conclusion: Deficiency of testosterone was arrhythmogenic in rat atria possibly through less binding of FKBP12.6 to RyR2, which could induce feasible calcium leakage from the sarcoendoplasmic reticulum. These results would explain, at least in part, the increase in the prevalence of AF in accordance with the decline of testosterone particularly in elderly men.